Breech mechanism.



I lTo all 'whom 'it muy concern .i

1,1's6,2ee.

UNITED sTATEs PATENT OEEIOE.

1 DORSEY FROST AsBURY. or WAsI-IINGTON.,DIsTRIOT or COLUMBIA, AssIeNoR -TO UNITED .sTATEs-ORDNANCE COMPANY, or WASHINGTON, DISTRICT or COLUMBIA, A CORPORATION or VIRGINIA.

Specification of Letters Pa'tent. i.

. BRRECH IvIEoII-ANIsIvI.4

' Appncation'fueu July 21, 1915. serial No. 41,063.-

Beit known that I, Dorsey F. Asiatin', a

l citizen of the United States. and resident of the city of lVashingtong in the 'District' of i Columbia, have invented certain new and.v usefullmprovements in Breech Mechanisms,

Ofwli'ich the following is a' specification.

'ployedlfor the purpose of `translating the swinging" movement of the vbreech plug into"v "ed threads of the plug., which cooperatesA y.with the threads A? in the'usual and well gas check My vinvention relates 4to breech mechanisnis and particularly that type of breech mechanism wherein a cani device 1seni rotarymovement., y i l In breech mechanisms ofthe type referred to a very strong mushroom spring is einployed in an' -effort'to prevent the mushroom iyingjforward in the operation' of closing isrequired to rotate the plug against the pads surface. IThese mushroom springs heretofore havel not been entirely successful in holdingvthe mushroom against -iying forward with the result that considera'ble of the energy stored in the mushroom necessary for the most effective operation of the cam device in translating motion is lost, while onthe other hand lthe rebound of the mushroom under the `iniluence of the relatively strong spring vwill cause chattering ofythe-bushing threads. andthe plug Itis therefore thef'dbject of my invention to reduce the'unit pressure between the rearsurface of the pad and the forward surface.

of the plug; to keep the mushroom from flying forward when the plugs swing home is i Weak spring arrested; to hold the pad lin place by a very i to hold the pad against the forward facel ofthe plug-by means reacting against the plug; to provide a structure by which the tension of the 'mushroom springv .is not affected bythe rotation of the plug;`

'I A.to avoid .anyepressure between the carrier and plug vthreads vandbetween the interrupted all the spindle plug and breech. bushing threads; to provide means whereb swinging energy of the mushroom can be l that can be l held and transmitted to plug 'rotation energy plug rotating cam; and to profor' attaining the above objects easily tted on breech mechanisms now 1n use.

through the vide means In the drawings chosen-"for the purpo'seeof.

' nut D2.

let, preferably lillustrating my invention. the scope whereof is pointed outinthe claim, Figure '1,is" a `horizontal section through a portion of the breech mechanism embodying the invention.

those parts of the mechanism not essential t0.an understanding of the invention being omitted for the 'sake of clearness. and Fig. 2; a section on the line 2 2 of Fig. l.

Referring -to the drawing `indicates ti gun-A the plug bushing A2 the i'iterriipt d vthreads ofthe plug bushing.

v B indicates the plugl and B the interi-uptgaged vin the. plug lBl andthe boie of the,

spindle C' This stem D carries the 'usual nut D2, that portion of the -bore of the A spindle in which the nut D2 is disposed being enlarged to forni a 4shoulder 10; The

swinging movement of the plug B' in the.

closing of the breech istranslated into a rotary movement by a cam device which may be of any desired construction, the only essential being that a cam device be employed for translating the swinging (movement of the plug into rotary movement as the-plug moves into the breech in order that the effectiveness of such cani device may be enhanced through the medium'oftherelated structure of the breech mechanism embodied in my invention. .l Interposed b tween the mushroom D and the front" face of the plug B is a gas check pad 11 embodying the usual rings-12. Disposed in the major portion of the4 bore of the spindle-C isa 'cup 13 situated betweenv the shoulder 10 andthe nut D2, the openen of said cupbeingv disposed adjacent ythe Slidably mounted in the carrier Vspindle C is a plurality of compression rods three in number, which bear at one end against the` 'closed endv of the cprl and their other end against a ring 1`5`which directly 'abutsthe plugB.. It Will be noted that'I only employ the-ring 15'` for the purpose. of getting ahardened surface for the rods 14 to act against vand forthe purposes of this invention suchring will be Patented J une 6, 1916.1 l

considered as a partof tliebreech plug.

Encircling the mushroom stem D is a relatively weak spring 16 which is disposed Within the cup 13 andbears at one end against the closed end of the cup and at its other end against the nut D2. This spring 1Gl actsv uponthe mushroom D to compress the pad 11 betweeinsam'e and the forward end of the plug B. By providing the cup 13 andinterposing saine between the shoulder 10 and the nut D2 I limit the forward movement of the mushroom ."to approxi-I mately three hundredths of an inch. s-ucli limitation of movement being effected b v engagement of the nut D2 with the cup 13 as will be obvious.

The action of the cani device forming an element of this invention takes place before the plug is vhome and the -pad seated and under such conditions if the mushroom were to fly forward and the gas check rings get out of their-.position in respect with the pad and the seat in the gun the energystoied in the mushroom would be lost with respect to lits utilization by the cam device in effecting vtranslation of motion. In addition the proper-'functioning of the gas check pad would be interfered with. By providing a positive Stop in the form of the cupl acting through the compression rods 1i against the plug B to lim'it lthe forward. movement of the mushroom I ain-enabled to conserve all the swinging energy of the mushroom for utilization by'the camdevice in trans-V lating the swinging motion of the plug to rotary motion and at the saine. time I obviate the possibility of the gas check rings getting out of their position. As the spring 16 n0 longer serves the purpose of holding.'

the mushroom aga-inst forwafrd movement it will be apparent that (my structure only l necessitates the use of ajrelatively weak y spring suflicient to hold the gas -check pad and ring taut.

By'arranging the mechanism so that thev v spring compressing means reacts against the plug-it will be obvious that rotation of the plug will not tighten or loosen-the tension of the spring even though the threads on the plug carrier spindle have a lead. By compressing the mushroom spring against Vthe plugvand not against thel carrier the threads on the carrier spindle areallowed to float during the plngs rotation and do not 55 offer any resistance due to the mushroom spring as heretofore and as these threads float the interrupted threads vonthe plugA and breechnbushingnaturally assume theireasiest rotating position, in otherwords the plug andbreech bushing threads also float.'

This iioating condition obviates a relatively large amount of friction and thereforeless power is needed to rotate the plugthroughv the medium of the cam device.

By providing the cup 13 and relatively small spring 16 I am enabled to t same in the yspace heretofore -used in mountingthe large strong spring. rier for the compression lrods 14C are drilled with. a jig which has only one'hole, the jig is turned for, the" drilling of theothei' holes.

The compression rod holes in the carrier do'V not weaken the spindle as they pass through an eXtra strong section.

That I claim and desire to secure by Letters Patent is In a gun, the combination of a swinging` carrier, a rotatable breech plugY` a inushroom, a cani device for translating the ino-v tion of the plug asgthe latter enters the breech, and non-elastic inea'ns for holding the -inushroom against forward movement' 

